Which sentence below is properly punctuated?
a.
bertie had several people working for him; a private secretary, an administrative assistant, and a research aide.
b.
bertie had several people working for him, a private secretary, an administrative assistant, and a research aide.
c.
bertie had several people working for him: a private secretary, an administrative assistant, and a research aide.

The right answer is the C) Bertie had several people working for him: a private secretary, an administrative assistant, and a research aide.

Explanation: Just to elaborate a little on the answer, it can be added that option A should be discarded, because a semicolon is commonly used to join two independent clauses, but the words "a private secretary, an administrative assistant, and a research aide" cannot stand on their own as a complete sentence. In addition, option B can also be discarded, since the words "a private secretary, an administrative assistant, and a research aide" can't be separated from the main clause by means of a comma, unless they are preceded by the preposition "like" or the idiom "such as." Option C is, therefore, the correct one. The colon is used here to introduce a list, specifically of names of professionals that worked for the subject, Bertie.  

faze apex of course.

because each is self-sufficient.